The present invention relates to a seat belt retractor.
EP 0893313 A1 teaches a seat belt retractor wherein the winding reel of a seat belt retractor is loaded with varying torques generated by an electric motor. The respective torques are transmitted via a mechanical switching mechanism whereby, depending on the respective switch position, the comfort perceived by the wearer of the seat belt, the belt webbing tightening, or a belt force limitation can be obtained.
There is provided in accordance with the present invention a seat belt retractor having a switching mechanism that is operated dependent on the number of revolutions, or dependent on the change in number of revolutions, with which the torque generated by the electric motor is transferred to the winding reel. A torque transferred with a low number of revolutions, respectively a low change in number of revolutions, causes the switching mechanism to assume a switch position ensuring the comfort perceived by the wearer of the seat belt, and a torque transferred with a higher number of revolutions causes the switching mechanism to assume a switch position ensuring the tightening of the belt.